Hopper door locking mechanism



Jun 23, 1959 Filed Nov. 16, 1956 c. HANKINS HOPPER DOOR LOCKINGMECHANISM I Q 4 Sheets-Sheet 1 INVENTOR cmus HAN/(INS BY .A ATTORNEYJune 23, 1959 c. HANKINS HOPPER DOOR LOCKING MECHANISM I Filed Nov. 16,1956 v Y 4 Sheets-sheaf 2 INVENTOR cmus HANK/N8 1% ATTORNEY June 23,1959 c, HANK|N$ HOPPER DOOR LOCKING MECHANISM 4 Sheets-Sheet 3 I FiledNov. 16, 1956 INVENTOR aww/s HAN/(INS A; ATTORNEY June 23, 1959 c.HANKINS 2,891,487

' HOPPER DOOR LOCKING MECHANISM Filed Nov. 16, 1956 4 Sheets-Sheet 4FIG] mvsmoa CYRUS HANK/N8 4; ATTORNEY atent i 2,891,487 Patented. June23, 1959 Free HOPPERJDOOR LQcKING. MECHANISM Cyrus Hankins, Washington,D.C., assignor to Unitcast Corporation, Toledo, Ohio, a corporation ofOhio Application November 16,1956, Serial No. 622,557

7 Claims. (Cl.'105-308) This invention'relates' to a hopper door lockingmechanism for individually locking a hopper door of a hopper car.

The individual locking of the hopper or drop bottom doors of a hoppercar poses a number of problems. For one, the door should be readilyreleasable. For another, the latching mechanism must be ableautomatically to engage and hold the door in'a preliminary position asit is swung shut'by' the operator. Fora third,'the door must be able tobe drawn'from'this preliminary position to closed position'regardlessofwarpage, so that it will provide an effective closure for the hopperopening. Additionally, for his protection,the operator should'be able tooperate the door entirely fromthe side of the car, during both openingand preliminary and fina'l'closing. Andlastly, and of prime importance,the locking mech anism should be contained, at minimum, within theA.A.R. unrestricted equipment lirni t' line at both sides and bottom ofthe car to enablethe car to be used in interchange and, at maximum,within a line representing side and'bottom clearances for a car justmeeting the minimum A.A.R. standards for coupling height. The individualdoor locking mechanisms heretofore proposed solve some of theseproblemsbutnoneemploying a single central latch solves them all.

It istherefore the primary object of the present invention to provide animproved individual door locking mechanism employing 'a single latch andsolving the various problems involved in individually locking hopperdoors.

Another object of the invention is to-provide' an improved individualdoor lo'cking mechanism wherein both a central-1y located latch memberand the operating mechanism therefor are carried bya hopper door and somounted as to be Within the side and bottom equipment limits even whenthe-car has dropped to the minimum permissiblecoupling height, theoperating mechanism at the same time providing a-handle for enabling anop erator to swing the door closed from the side of the car.

A further object of the invention is-to provide a mechanism for.individually locking a hopper door which is applicable equally whetherthe doors swing individually or are connected to swing in pairs.

An additional object of the invention is to provide animproved-mechanism for individuallylocking a hopper door which not onlyprovides a preliminary hold which automatically engages as the. door isswung-shut and'a mechanical advantage ample for thedoor to'be pulledtighty-tofully'closed position,.but.also effectivelylocks the operatingand latchingymechanisms against accidental dislodgement. when the dooris infu'lly closed: position.

Another object. of the invention is to provide. .an improved. lockingmechanism for .a hopper door wherein,

while carried by andlocated substantially centrally of. the bottom edgeof the, door, the latch member is ob-.

liquely disposed relative to.that edge. so asto afford max.- imum railclearance;

Other objects and advantages of'the invention will appear hereinafter inthe detailed description," be particu- 2. larly pointed out in theappended claims and, be illustrated in the accompanying drawings, inwhich Figure l is a sectional view of a hopper door and the associatedportion of a hopper car with the door locked in closed position by apreferred form..of the locking mechanism of the present invention, the.latter. being shown in side elevation;

Figure 2 is a front view on a reducedscale andtaken in the plane of thedoor of the structure. of Figure 1;.

Figure 3 is a fragmentary sectional view corresponding to the lowerportion of Figure 1 .b'llt withthedoorpalitly: open;

Figure 4 is a fragmentary sectional view onanenlarged scale takenalongthelines. 44 of Figure 2;

Figure 5 is a. fragmentary view on the scale of. and taken-on the samesection as Figure 4. with. the doorin the partly open position of Figure3;

Figure 6 is an exploded isometric view of the locking mechanisms latchmember and operating shift; and.

Figure 7 is a fragmentary front elevational view of the structure ofFigure 1.

Referringnow in detail to the drawings, in. which like referencecharacters designate like parts, the improved locking mechanism of thepresent invention is applicable generally for individually lockinghopper. doors and may be applied to hopper doors .of..rectangular,trapezoidal or other shape. Since the operationof the-lockingmechanismwill be the'same, Whether the particular. door to which it is-applied isoperated fromone side or the other, the installation differing only inuse of the counterparts of certain of the parts, a door operated fromthe left side has been selected for purposes of illustration. Also, asexemplary of the invention, the particular hopper or drop bottom door,designated asl, to which the locking. mechanism has been applied is ofrectangular shape and the part of the hopper car (not shown) to whichthetop of the door is hinged or pivoted is a door frame. 2 bound.-. ing theopening3 in ahopper 4, having the usual downwardly ,bottomvslope-sheetor slopingbottom wall 5 and. inwardly slopingouter side wall 6.

Asthe hoppers and hopper doors of a hopper car project below the levelof the, bodiesof other types: of freight. cars and are located at thesides of thecar, the provision of an eflicient locking-mechanism whichwill.clear the track over vertical curves and track installations atthev sides of horizontal curves presents difficultieswhichbecomeparticularly acute when, as here, it is desired to. employ .a singlelatch member. As illustrative of these difficulties, there are shown inFigure 7 the disposition of a closed door on a new hopper car relativeto the head.

7' of the rail at the corresponding side of theitrack and:

the equipment limitlines determinative of the extent relative to thecenter of the track that the equipment can. project from the adjacentside and bottom of the car.

Three equipment lines have been shown, one, designated as A-A, theA.A.R. equipment limit line for an electric.

section ontan gent track, and another,.BB, the A.A.R.. unrestrictedequipment diagram for interchange service. The third line CC is the lineAA transposed to take into account both lateral offset of-acaronmainlinehori zontal curves and the permissible drop-of .some threeinches in the coupling height of a cardue to. wear before. a car isdeclared unfit for interchange, service. The line.

C'CalloWs for. this drop, as well as for theincreased dividu'aldoorlocking. mechanisms employing a single central'latch member to mount thelatch member and opera ating mechanism on the bottom sheet.5 of the.hopper.

rather than on the door or, if the mechanism is door mounted, to raisethe level of the mechanism by providing a hole in the lower portion ofthe door through which the latch projects in engaging a catch mounted onthe inner face of. the bottom sheet of the hopper. The second of theseexpedients, of course, is subject to the objection that the catch withits housing interrupts and impedes flow of lading through the hopperopening and the first leaves the operator with the necessity of eitherusing his foot or grasping a handhold especially provided for thepurpose in order to swing the door to closed position.

The locking mechanism of the present invention not only permits theoperating mechanism to be mounted on the door without cutting the dooror interrupting the hopper opening, but enables its components to beheld well within even the minimum limits imposed by the equipment lineCC. This, in the main, is accomplished by rockably or pivotally mountinga latch, latch member or latching pawl 8 on the outer face 9 of the door1, adjacent and substantially centered laterally relative to the bottomedge or margin 10 of the door, with the rocking or pivotal axis of thelatch extending diagonally from the center towards the upper edge 11 ofthe door and inclined or oblique relative to both the bottom edge 10 andthe vertical center line of the door. The latch in one direction fromits axis extends below and inwardly or. rearwardly beyond the bottomedge 10 of the door and terminates at its lower inner end in a hook orhooked nose portion 12, the latch carrying at its opposite end acounterweight 13.

Mounted and fixed as by welding to the bottom slope sheet or wall 5, orin the disclosed embodiment the corresponding portion of the door frame2, is a catch, catch member or keeper-plate 14 disposed in line with thelatch 8 and having a shoulder or abutment 15 engageable by the hook 12on the latch 8 for locking the door in place. So that the hook 12 willride or slide into engagement with the shoulder 15 as the door 1 isswung shut, the front face 16 of the hook 12 or the outer,door-confronting, surface 17 of the shoulder 15 and preferably both, arebevelled or slanted so as to cam the lower or hook carrying end of thelatch downwardly against the weight of the counterweight 13 and clearthe bottom edge or crest 18 of the shoulder 15.

The latch 8 rocks on an eccentric cylindrical inner portion 19 of anoperating shaft or rod 20, the main portion 21 of which projects orextends beyond the outer edge 11 of the door 1 and there terminates in asocketed head or outer end portion 22, the socket 23 in which isdisposed at an angle to the axis of the main portion 21 and, in thelocked position of the operating shaft 20, is substantially parallel tothe outer side wall 6 of the hopper, the head, as shown in Figure 2,lying closely adjacent the side wall 6 of the hopper 4 and being wellwithin the line CC. For journalling the operating shaft for rotation orturning on the door 1 there is provided a mounting bracket 24 carrying apair of longitudinally spaced, concentrically or coaxially aperturedhearings or hearing blocks 25, in each of which fits or seats and isjournalled one of a pair of annular collars or flanges 26 coaxial withand spaced axially of the main portion 21 of the operating shaft 20.

In the preferred embodiment, the mounting bracket 24 is of angle sectionwith one leg 27 fixed or secured as by welding or riveting to the outerface 9 of the door 1 and the other leg 28 projecting outwardlysubstantially normal to the door, the bracket bending obliquelysubstantially at its center with its outer portion 29 extendingsubstantially parallel to the operating shaft 20 and its inner portion30 following the bottom edge 10 of the door. With this construction, thebearings may form some of the ribs or webs connecting and reinforcingthe legs 27 and 28. Inwardly beyond its eccentric portion 19 theoperating shaft 20 terminates in an inner end portion 31 concentric orcoaxial with but of less diameter 4 than the main portion 21 and seatingin and extending through a socketed boss, hearing or hearing block 32fixed to or integral with the mounting bracket 24.

The purpose of the eccentric mounting of the latch 8 is to enableleverage to be applied through an actuating lever in the form of a baror rod (not shown) insertible in the socket 23 in the head of theoperating shaft 20 after the hook 12 on the latch 8 and shoulder 15 onthe catch 14 have engaged to hold the door in a preliminary hold orclosed position as it is swung shut or towards closed position, so as toenable the door to be drawn up tight to fully closed position. To thisend, the eccentric portion 19 has its axis so disposed relative to thatof the main axis of the operating shaft 20 as to be at maximum lateraldisplacement or eccentricity relative to the plane of the outer face 9of the door 1 and thus the catch 14, when the door is fully closed, asshown in Figure 4.

While such eccentricity, alone, by progressively shifting the rockingaxis of the latch 8 outwardly, would pull the door up tight, a drivableconnection between the latch 8 and the operating shaft 20 is needed todisengage the hook 12 from the catch 14 when the door is being openedand, conversely, to hold the hook and the catch in engagement under theclosing pressure applied through the operating shaft under force of theactuating lever. Such a drivable connection with the lost motion neededto enable the latch 8 to rock freely through a limited are so that itwill automatically engage the catch 14 as the door is swung shut, may beprovided by one or, in the disclosed embodiment, a pair of lugs 33projecting radially from the eccentric portion 19 at one or, if a pairis employed, either side of the hub 34 of the latch 8. Each of theselugs 33 is contained or rides in a segmental slot 35 interrupting eachof a pair of segmental annular skirts or shoulders 36, one projectingfrom each side of the latch 8 axially of its hub.

Although the eccentric portion 19 could be rotated through a full 180between the hold or preliminary closed and the closed positions of thedoor, the displace ment obtainable with a rotation has been found sufiicient and the corresponding lost motion or are of relative movement ofthe latch relative to the operating shaft is quite adequate to enablethe hook 12 to engage and disengage the catch 14. As a consequence, thearc of the segmental slot 35 in each skirt 36 in the disclosedembodiment is about 90, so that each lug 33 will swing at maximumthrough a somewhat lesser are before one or the other of its sides 37engages the confronting of the circumferentially spaced abutments 38 onthe associated of the skirts 36 defining the opposite edges of itssegmental slot 35.

With the above lost motion drive or connection between the latch 8 andthe operating shaft 20, rotation of the operating shaftcounterclockwise, as viewed from its head 22, when the door is fullyclosed, will shift the rocking axis of the latch 8 laterally toward thecatch 14, freeing the bottom edge 10 of the door 1 from the hopper 4. Asthe rotation approaches 90, the abutment 38 at the far edge of eachsegmental slot 35 in the skirt 36, is engaged by the associated of thelugs 33, causing counterclockwise rotation of the latch 8, and forcingthe hook 12 downwardly until it clears the crest 18 of the shoulder 15on the catch 14, whereupon, the door is free to swing open. Sincerotated on opening of the door 1 to the position shown in Figure 5 inwhich its hook 12 is below the catch 14, the latch 8, if it remained inthat position, would not reengage the catch as the door was swungclosed. However, once the latch 8 is released from the catch 14 and theactuating lever (not shown) by which the operating shaft 20 was rotatedto open the door is removed from the socket 23, the counterweight 13 onthe latch will come into play and apply the necessary force through thelug or lugs 33 to rotate the operating shaft-sufliciently to enable thelatch, to: assume the.- rotativeposition shown in Figure.4,-- wher,eatit-isadapted to reengage the catch 14. After. the-contents of the hopper4 have been dumped, an operator has merely. to grasp the projectinghead-22 of. theoperating shaft 20 and, using it. as a handle, swingthe,..door 1 to latchandcatch engaging or hold position. Thereafter, hewill insert an actuating lever (not shown) intothe socket, 23 and, byrotating the operating,;shaft clockwise; shift the. eccentric portion 19outwardly and, by engagement of the lug or lugs 33 with the-opposite ofthe abutment or abutments 38 on the skirt or skirts 36,-force the hook12 upwardly relative to-the shoulderlS on the catch until the latch hasfinally reached the closed position shown in Figure 4.

border to prevent accidental releasing of the latch 8'when the door isclosed, there is mounted on the outer face 9 of the. door, as through athimble '39 and rivet 40,;a cam, 41 preferably having a plurality ofrelatively stepped teeth or ridges 42, an adjoining pair of which is;adapted to engage; the inner wall 43 of a longitudinally or axiallyextending groove or slot 44 in the operating shaft 20 with which the cam41 aligns when the operating shaft is rotated such that the eccentricpor- 'tion 19 is in its outermost or door locked position.

As. willbe noted from Figure 6, the eccentric portion 19. and thelug orlugs 33 are confined, radially of the operating shaft 20, within theperimeter of the annular flanges 26 through which the operating shaft isjournalled in the mounting bracket 24, this preferred constructionserving to enable the eccentric and lug or lugs to be inserted throughthe bearings 25 as the operating shaft is installed.- If, as in thedisclosed embodiment, a pair of driving lugs 33 is employed, the bore 45of the latch 8 which embraces or slides on the eccentric portion '1? isinterrupted by an-axially extending key slot 46 through which the innerof thelugs 33 may slide until it reaches its. assembled position beyondthe bore and within the segmental slot 35 in the inner of the skirts 36.The reduced inner end portion 31 of the operating shaft will thenbeseated in its bearing 32 and project therebeyond so; as to receive acotter. pin or like retaining means 47 for holding the operating shaft,against displacement axiallyof the mounting bracket.

It has been mentioned that the illustrated locking mechanism, applied toa door operated from the left side, is; exemplary of the application ofthe latching mechanism to doors operated from either side. The operatingshaft, 20 and the 1atch'8 of the illustrated embodiment may be-usedwithout change on either door, thus, for a door ,operate'd'from theright side, making it necessary only to substitutefor the mountingbracket 24, the catch 14 and the. cam 41, their counterparts. Fittedwith such lockingmechanisms, the several hopper doors of a hopper-carmay be operated individually. If desired, they may also be operated inpairs, one at either side of the; car,,so as to preventone side of thecar from being unloaded first and consequent overturning of the car dueto the shifting of its' center of gravity, as "sometimes occurs. Forsuch pair operation, it is only necessary that each pair of doors beconnected beneath the center sill,(no.t shown) of the car by an angleiron or like suitable rigid, means (not shown), spanning and spacedbelow the center sill of the car and fixed at its ends to the outerfaces 9 of the two doors.-

Fromthe. above detailed description it will be. apparent that there hasbeen provided an improved individual door locking mechanism for hopeprdoors which not only affords a preliminary hold position, enables thedoor to be drawn up tight and positively unlocks the door but also,without encroaching upon even the most restrictive of equipment limitlines, has its operating mechanism mounted on a door and therethroughprovides a handle for swinging the door closed. It should be understoodthat the described and disclosed embodiment is merely exemplary of theinvention and that all modifications are-intended tobe included which donot'depart from either. the spirit of they invention or the scope of theappendedclaims.

Having described my invention, what I claim is:

1. The combination witha top hinged door for closing a discharge openingin a hopper of a hopper car, of a door locking mechanism comprising alatch mounted on an outer face of said'door anddisposed obliquely to andprojecting belowa bottom edge of said door substantially centrallythereof, an operating shaft rotatably mounted on said outer face of saiddoor and having an eccentric portion ,rockably mounting said latch, saidoperating shaft extendingfrom said latch along said outer face of saiddoor at an inclination to said bottom edgev thereof and having anouterend portion projecting-beyond a side of said door,- lost motionmeans drivably connecting said latch and shaft, and a catch secured to abottom of said hopper, said catch being automatically engageable by saidlatch on swinging of said door, toward closed position, and said latchon subsequent rotation of said shaft having its rocking axis shiftedoutwardly relative to said door and through said lost, motion meanshaving its lower end portion swung upwardly relative to said catch inmoving said door to closed position.

2. The combination with a top hinged door for closing a dischargeopening'in a hopper of a hopper car, of a door locking mechanismcomprising a latdh member mounted on an outer face of said door anddisposed diagonally relative to and substantially centrally of a bottomedge of said door, said latch member having a hook portion extendingbelow and rearwardly of said outer face beyond said edgeand acounterweighted opposite end portion, an operating shaft rotatablymounted on and extending along said outer face of said door at anincline to said bottom edge, said operating shaft having an eccentricinner portion rockably mounting said latch and an outer end-portionprojecting beyond a side of said door, lost motion means drivinglyconnecting said latch and shaft, and a catch secured to a bottom of saidhopper, said catch being automatically engageable by said latch onswingingof said door toward closed position, and said latch onsubsequent rotation of said shaft, having its rocking axis shiftedoutwardly relative to said door and through said lost motion meanshaving its lower end portion swung upwardly-relative to said catch invmoving said door to closed position.

3-. The combination with a top hinged door for closing a dischargeopening in, a hopper of a hopper car, of a door locking mechanismcomprising a latch member mounted on an outer face of said door anddisposed diagonally relative to and substantially centrally of a bot tomedge of said door, said latch member having a hook portion extendingbelow and rearwardly of said outer face beyond said edge and acounterweighted opposite end. portion, an operating shaft rotatably.mounted on and extending along said outer face of said door at anincline to said bottom edge, said operating shaft having an eccentricinner portion rockably mounting said latch and a handle portionproiecting beyond a side, of said door, lug means, on said eccentricportion and riding between and alternately engageable, with,circumferentially spaced abutment means. carried by said latch member,and a catch secured to a bottom of, said hopper and automatically;engaged by the hook portion of said latch membet on swinging of saiddoor toward closed position, subsequent rotation of said shaft in onedirection shifting the rocking axis of said latch member outwardly andby engagement of said lug means with certain of said abutment means,swinging said hook portion upwardly relative to said latch for movingsaid door to closed position, and rotation of such shaft in the oppositedirection when said door is closed shifting said rocking axis inwardlyand by engagement of said lug means with other of said abutment meansswinging said hook portion downwardly for disengaging said latch memberfrom. said catch.

4. The combination with a top hinged door for closing a dischargeopening in a hopper of a hopper car, of a door locking mechanismcomprising a latch member mounted on an outer face of said door anddisposed diagonally relative to and substantially centrally of a bottomedge of said door, said latch member having; a hook portion extendingbelow and rearwardly of said outer face beyond said edge and acounterweighted opposite end portion, an operating shaft rotatablymounted on and extending along said outer face of said door at anincline to said bottom edge thereof, said operating shaft having aneccentric inner portion rockably mounting said latch member and asocketed head projecting beyond a side of said door and lying closelyadjacent a side wall of said hopper, the socket in said head beingadapted to receive an actuating lever and in the closed position of saiddoor being disposed substantially parallel to said side wall, a campivotally mounted on an outer face of said door and aligning andengageable with a slot extending longitudinally of said shaft when thedoor is in closed position for locking said shaft against accidentalrotation, and a catch secured to a bottom of said hopper, said catchbeing automatically engageable by said latch on swinging of said doortoward closed position, and said latch on subsequent rotation of saidshaft having its rocking axis shifted outwardly relative to said doorand through said lost motion means having its lower end portion swungupwardly relative to said catch in moving said door to fully closedposition.

5. The combination with a top hinged door for closing a dischargeopening in a hopper of a hopper car, of a door locking mechanismcomprising a latch member mounted on an outer face of said door anddisposed diagonally relative to and substantially centrally of a bottomedge of said door, said latch member having a hook portion extendingbelow and rearwardly of said outer face beyond said edge and acounterweighted opposite end portion, an operating shaft rotatablymounted on and extending along said outer face of said door at anincline to said bottom edge, said operating shaft having an eccentricinner portion rockably mounting said latch and an outer end portionprojecting beyond a side of said door, annular wings projecting fromopposite sides of said latch member and each interrupted by a segmentalslot, lug means projecting radially from said eccentric portion of saidshaft and riding in at least one of said slots, and a catch secured to abottom of said hopper and automatically engaged by the hook portion ofsaid latch member on swinging of said door toward closed position,subsequent rotation of said shaft in one direction shifting the rockingaxis of said latch member outwardly and by engagement of said lug meanswith certain of said abutment means swinging said hook portion upwardlyrelative to said latch for moving said door to closed position, androtation of such shaft in the opposite direction when said door isclosed shifting said rocking axis inwardly and by engagement of said lugmeans with other of said abutment means swinging said hook portiondownwardly for disengaging said latch member from said catch.

6. The combination with a top hinged door for closing a dischargeopening in a hopper of a hopper car, of a door locking mechanismcomprising a latch member mounted on an outer face of said door anddisposed diagonally relative to and substantially centrally of a bottomedge of said door, said latch member having a hook portion extendingbelow and rearwardly of said outer face beyond said edge and acounterweighted opposite end portion, an operating shaft rotatablymounted on and extending along said outer face of said door at anincline to said bottom edge, said operating shaft having an eccentricinner portion seatnig in a bore of and rockably mounting said latchmember and an outer end portion projecting beyond a side of said door,annular wings projecting from opposite sides of said latch member andeach interrupted by a segmental slot, a pair of lugs spaced axially ofand projecting radially from said eccentric portion and each riding inone of said slots, 21 key slot interrupting the bore of said latchmember for passing one of said lugs therethrongh, and a catch secured toa bottom of said hopper and automatically engaged by the hook portion ofsaid latch member on swinging of said door toward closed position,subsequent rotation of said shaft in one direction shifting the rockingaxis of said latch member outwardly and by engagement of said lug meanswith certain of said abutment means swinging said hook portion upwardlyrelative to said latch for moving said door to closed position, androtation of such shaft in the opposite direction when said door isclosed shifting said rocking axis inwardly and by engagement of said lugmeans with other of said abutment means swinging said hook portiondownwardly for disengaging said latch member from said catch.

7. The combination with a top hinged door for closing a dischargeopening in a hopper of a hopper car, of a door locking mechanismcomprising a bracket secured to an outer face of said door adjacent abottom edge thereof, an operating shaft rotatably mounted on saidbracket and extending diagonally along said outer face of said door frombeyond a side substantially to the center there of, said shaft having aneccentric inner portion and outwardly of said side of said door asocketed head for receiving an actuating lever, a latch member rockingon said eccentric portion about an axis oblique to said bottom edge andhaving a hook end portion extending from said outer face below andrearwardly beyond said bottom edge and a counterweighted opposite endportion, lug means on said eccentric portion and riding betweencircumferentially spaced abutment means carried by said latch member forlimiting the rocking movement of said latch member relative to saidshaft, and a catch member secured to a bottom of said hopper andautomatically engaged by said latch member on swinging of said doortoward closed position, subsequent rotation of said shaft in onedirection shifting the rocking axis of said latch member outwardly andby said lug and abutment means swinging said hook portion thereofupwardly relative to said catch member for closing said door, androtation of said operating shaft in the opposite direction when saiddoor is closed shifting said rocking axis inwardly and swinging saidhook portion downwardly for disengaging said latch and catch members andreleasing said door.

References Cited in the file of this patent UNITED STATES PATENTS827,526 Gibson July 31, 1906 2,482,516 Sheesley Sept. 20, 1949 2,730,966Dorey Jan. 17, 1956 FOREIGN PATENTS 484,033 Canada June 17, 1952

